Efficacy of a behavior change program on cardiovascular parameters in patients with hypertension: a randomized controlled trial / Eficácia de um programa de mudança de comportamento sobre parâmetros cardiovasculares em pacientes com hipertensão arterial sistêmica: ensaio clínico controlado randomizado

ABSTRACT Objective To investigate the efficacy of a behavior change program named Vida Ativa Melhorando a Saúde on cardiovascular parameters in hypertensive patients. Methods Ninety hypertensive patients aged over 40 years were randomly allocated to one of two groups: Vida Ativa Melhorando a Saúde or Control (n=45 respectively). Patients in the Vida Ativa Melhorando a Saúde group took part in a behavior change program aimed to encourage changes in physical activity levels and eating habits, according to the Social Cognitive Theory. The program consisted of 90-minute weekly group meetings conducted by a physical therapist and a dietitian. One chapter of the educational material (workbook) provided was discussed per meeting. Participants in the Control Group attended a single educative lecture on lifestyle changes. Brachial and central blood pressure, arterial stiffness and endothelial function parameters were measured pre- and post-intervention. Results Vida Ativa Melhorando a Saúde led to reduction of brachial (131.3±15.8mmHg to 125.1±17.3mmHg; p<0.01) and central (123.6±16.3mmHg to 119.0±20.6mmHg; p=0.02) systolic and brachial diastolic (123.6±16.3mmHg to 119.0±20.6mmHg; p<0.01) blood pressure values, and improvement of post-occlusive reactive hyperemia (from 5.7±2.5mL·100mL−1 to 6.5±2.1mL·100mL−1 tissue·min−1; p=0.04). No changes in body composition, heart rate and arterial stiffness parameters were detected in both groups (p>0.05). Conclusion Vida Ativa Melhorando a Saúde program improved blood pressure and microvascular reactivity in hypertensive patients. Trial registration: ClinicalTrials.gov: NCT02257268

RESUMO Objetivo Analisar a eficácia do programa de mudança de comportamento Vida Ativa Melhorando a Saúde sobre parâmetros cardiovasculares em pacientes hipertensos. Métodos Noventa pacientes hipertensos ≥40 anos foram aleatoriamente randomizados em dois grupos: Vida Ativa Melhorando a Saúde (n=45) e Controle (n=45). O Grupo Vida Ativa Melhorando a Saúde participou de um programa de mudança de comportamento que objetiva motivar mudanças na atividade física e nos hábitos alimentares, de acordo com a teoria sociocognitiva. O programa foi conduzido em grupos, durante 12 semanas consecutivas, em encontros semanais (~90 minutos), conduzidos por um profissional de edução física e um nutricionista. Um capítulo do material didático era discutido em cada um desses encontros. O Grupo Controle participou de uma única palestra educativa sobre mudanças de estilo de vida. Medidas de pressão arterial braquial e central, rigidez arterial, e de função endotelial foram realizadas nos momentos pré e pós-intervenção. Resultados O Grupo Vida Ativa Melhorando a Saúde reduziu a pressão arterial sistólica braquial (de 131,3±15,8mmHg a 125,1±17,3mmHg; p<0,01) e central (de 123,6±16,3mmHg a 119,0±20,6mmHg; p=0,02) e a pressão arterial diastólica braquial (123,6±16,3mmHg a 119,0±20,6mmHg; p<0,01) e apresentou melhora na hiperemia reativa pós-oclusão (de 5,7±2,5mL·100mL−1a 6,5±2,1mL·100mL−1tecido·min−1; p=0,04). Não houve modificação na composição corporal, na frequência cardíaca e nem nos parâmetros de rigidez arterial em ambos os grupos (p>0,05). Conclusão O Programa Vida Ativa Melhorando a Saúde melhorou a pressão arterial e a reatividade microvascular em pacientes hipertensos. Registro do estudo: ClinicalTrials.gov: NCT02257268

A novel effective method for the assessment of microvascular function in male patients with coronary artery disease: a pilot study using laser speckle contrast imaging

Evaluation of microvascular endothelial function is essential for investigating the pathophysiology and treatment of cardiovascular and metabolic diseases. Although laser speckle contrast imaging technology is well accepted as a noninvasive methodology for assessing microvascular endothelial function, it has never been used to compare male patients with coronary artery disease with male age-matched healthy controls. Thus, the aim of this study was to determine whether laser speckle contrast imaging could be used to detect differences in the systemic microvascular functions of patients with established cardiovascular disease (n=61) and healthy age-matched subjects (n=24). Cutaneous blood flow was assessed in the skin of the forearm using laser speckle contrast imaging coupled with the transdermal iontophoretic delivery of acetylcholine and post-occlusive reactive hyperemia. The maximum increase in skin blood flow induced by acetylcholine was significantly reduced in the cardiovascular disease patients compared with the control subjects (74 vs 116%; P<0.01). With regard to post-occlusive reactive hyperemia-induced vasodilation, the patients also presented reduced responses compared to the controls (0.42±0.15 vs 0.50±0.13 APU/mmHg; P=0.04). In conclusion, laser speckle contrast imaging can identify endothelial and microvascular dysfunctions in male individuals with cardiovascular disease. Thus, this technology appears to be an efficient non-invasive technique for evaluating systemic microvascular and endothelial functions, which could be valuable as a peripheral marker of atherothrombotic diseases in men.

Endothelial dysfunction in primary Sjögren syndrome / Disfunción endotelial en el síndrome de Sjögren primario

OBJECTIVE: In this study, we aimed to investigate endothelial functions in primary Sjögren syndrome. METHODS: Thirty-five patients with primary Sjögren syndrome and 20 age and sexmatched healthy volunteers were recruited to the present study. Flow mediated dilatation of brachial artery and carotid intimamedia thickness were measured in the study population. RESULTS: Carotid intimamedia thickness values were similar between groups (0.50 ± 0.10, 0.53 ± 0.08, p > 0.05). Flow mediated dilatation of the brachial artery was disrupted in the primary Sjögren syndrome group (7% vs 12%, p = 0.002). CONCLUSION: There is endothelial dysfunction in patients with primary Sjögren syndrome, although they had comparable carotid intimamedia thickness with the healthy control group.

OBJETIVO: Este estudio se encaminó a investigar las funciones endoteliales en el síndrome de Sjögren primario. MÉTODOS: Para el presente estudio, se reclutaron treinta y cinco pacientes con síndrome de Sjögren primario y 20 voluntarios sanos apareados por edad y sexo. La dilatación mediada por flujo observada en la arteria braquial, y el espesor íntimamedia carotídeo fueron medidos en la población bajo estudio. RESULTADOS: Los valores del espesor íntimamedia carotídeo fueron similares entre los grupos (0.50 ± 0.10, 0.53 ± 0.08, p > 0.05). La dilatación mediada por flujo de la arteria braquial, estaba alterada en el grupo de síndrome del Sjögren primario (7% frente a 12%, p = 0.002). CONCLUSIÓN: Hay una disfunción endotelial en los pacientes con el síndrome de Sjögren primario, aunque estos tenían un espesor íntimamedia carotídeo comparable con el grupo de control saludable.

Occlusive hyperemia and normal pressure break through- physiopathology and management

Immediately following surgical excision of a cerebral AVM, even normal brain tissue surrounding the lesion is subject to hemorrhage, a phenomenon termed normal perfusion pressure breakthrough (NPPB) syndrome or occlusive hyperemia. According to this theory, arteries supplying cerebral AVMs become dilated and lose their capacity to dilate or constrict to autoregulate pressure. Acutely after removal of a cerebral AVM, excessive blood pressure in these arterial feeders can cause normal brain tissue to bleed. However, this theory still remains controversial.

Estudo da reatividade vascular em portadores de HIV com e sem uso de inibidor de protease / Study of vascular reactivity in HIV patients whether or not receiving protease inhibitor

FUNDAMENTO: Considerando o alto número de pacientes infectados por HIV em uso de antirretrovirais, evoluindo com alteração da função endotelial e aterotrombose, levando ao alto custo médico social, é importante identificar mecanismos fisiopatológicos envolvidos com a função endotelial em portadores de HIV, para que, precocemente, possamos intervir e evitar a progressão da doença. OBJETIVO: Avaliar a função endotelial pela vasodilatação endotélio dependente e independente em pacientes HIV positivo e em grupo controle. MÉTODOS: O estudo avaliou 27 pacientes HIV positivo e 16 do grupo controle. A avaliação da função endotelial foi realizada por meio da vasodilatação da artéria braquial endotélio dependente (hiperemia reativa) e independente (nitroglicerina SL). RESULTADOS: Pacientes HIV positivo em uso de inibidor de protease (IP) apresentaram vasodilatação endotélio independente significativamente menor que os subgrupos HIV negativo (p = 0,020) e HIV positivo sem uso de IP (p = 0,034). A variação do diâmetro da artéria braquial durante hiperemia reativa não apresentou significância estatística em qualquer subgrupo. A análise de regressão linear múltipla mostrou que apenas o IP estava associado ao delta relativo da reatividade braquial pelo vasodilatador, nos pacientes HIV positivo, aos 60 e 90 segundos. CONCLUSÃO: Os pacientes HIV positivo em uso de IP apresentam disfunção endotélio independente quando comparados a pacientes HIV positivo que não fazem uso de IP e a um grupo controle.

BACKGROUND: A great number of HIV-infected patients using antiretroviral drugs develop endothelial dysfunction and atherothrombosis, which lead to a high medical and social burden. Thus, it is important to identify pathophysiological mechanisms involved with the endothelial function in these patients, so that early intervention can be made to avoid disease progression. OBJECTIVE: To evaluate endothelial function using endothelium-dependent and independent vasodilation in HIV-positive patients and in a control group. METHODS: A total of 27 HIV-positive patients and 16 controls were evaluated. Endothelium-dependent (reactive hyperemia) and independent (SL nitroglycerine) vasodilation of the brachial artery was used to evaluate the endothelial function. RESULTS: HIV-positive patients receiving protease inhibitors (PI) showed significantly lower endothelium-independent vasodilation than the HIV-negative (p=0.020) and HIV-positive without PI (p=0.034) subgroups. The change in brachial artery diameter during active hyperemia was not statistically significant in any subgroup. Multiple linear regression analysis showed that only PI was associated with the relative delta of brachial reactivity to vasodilator in HIV-positive patients at 60s and 90s. CONCLUSION: HIV-positive patients receiving PI presented endothelium-independent dysfunction when compared to HIV-positive patients not receiving PI and to the control group.

Infrared imaging contribution for intestinal ischemia detection in wound healing / Contribuição da imagem infravermelha para detecção da isquemia intestinal na cicatrização das feridas

PURPOSE: To study thermal variations obtained through infrared image in rats, and to evaluate the relationship between intestinal ischemic time and histopathological findings. METHODS: Thirty Wistar rats were operated after distribution in 5 groups with different times of ischemia. Thermograms were obtained by using a infrared camera. The surgical technique has been standardized for all groups: abdominal cavity opening by a 5cm length incision in the midline, abdominal wall plans section and cavity exposure, and exteriorization of the intestine. In group I (control), it was proceeded only laparotomy without superior mesenteric artery ligature. After first thermogram done, incision was closed with continuing suture. In each rat in groups II, III, IV and V, the superior mesenteric artery was located at its origin on abdominal aorta, dissected and occluded with a vascular microclamp, subjecting the intestine to ischemia in variable times. RESULTS: Rats submitted to a 30 minutes ischemia presented reactive hyperemia, thermal differential of 1.8°C and normal pathological examination. The 1 hour ischemia produced reactive hyperemia with ischemic areas, thermal differential of 1.0°C and injuries at villosities' tips. However, the 90 minutes ischemia had not shown reactive hyperemia with large ischemic areas, thermal differential of -1.0°C and injury in the upper third of the villosities. The 2 hours ischemia demonstrated a severe ischemia, thermal differential of -2.0°C and injury throughout the all villosities' extension. CONCLUSION: It has been possible studying thermal variations through infrared image in rats, showing correlation between thermal response in thermograms, ischemic time and histopathological findings.

OBJETIVO: Estudar as variações térmicas obtidas por meio da imagem infravermelha em ratos, e avaliar sua correlação com o tempo de isquemia intestinal e os achados histopatológicos. MÉTODOS: Trinta ratos Wistar foram operados após distribuição em cinco grupos com diferentes tempos de isquemia. Os termogramas foram obtidos utilizando-se uma câmera infravermelha. A técnica operatória foi padronizada para todos os grupos, abertura da cavidade abdominal por uma incisão na linha média de 5 cm de comprimento com secção de todos os planos da parede abdominal e exposição da cavidade e as alças intestinais exteriorizadas. No grupo I (controle) foi feito apenas laparotomia sem ligadura da artéria mesentérica superior. Após realizado o primeiro termograma, foi fechada a incisão com sutura contínua. Em cada rato dos grupos II, III, IV e V a artéria mesentérica superior foi localizada em sua origem na aorta abdominal, dissecada com e ocluída por um microclampe vascular submetendo o intestino à isquemia em tempos variáveis. RESULTADOS: Os ratos submetidos à isquemia de 30 minutos apresentaram hiperemia reativa, diferencial térmico de 1,8°C e exame anatomopatológico normal. A isquemia de 1 hora produziu hiperemia reativa com áreas de isquemia, diferencial térmico de 1,0°C e lesões na ponta das vilosidades. Já a de 90 minutos não demonstrou hiperemia reativa com grandes áreas de isquemia, diferencial térmico de -1,0°C e lesão no terço superior das vilosidades. A isquemia de 2 horas mostrou isquemia grave, diferencial térmico de -2,0°C e lesão em toda a extensão das vilosidades. CONCLUSÃO: Foi possível estudar as variações térmicas por meio da imagem infravermelha em ratos, que mostrou haver correlação entre a resposta térmica dos termogramas, o tempo de isquemia e achados histopatológicos.

Exercício resistido na avaliação da disfunção endotelial na insuficiência cardíaca / Resistive exercise in the evaluation of endothelial dysfunction in heart failure

OBJETIVO: Avaliar o uso de exercício físico resistido no estudo da disfunção endotelial na insuficiência cardíaca comparativamente à hiperemia reativa (HR). MÉTODOS: Dezoito portadores de insuficiência cardíaca (IC) e 15 voluntários realizaram esforço físico manual de preensão intermitente em bolsa pneumática com intensidade correspondente a 75 por cento da carga máxima previamente avaliada. Foram avaliados por ultra-sonografia vascular de alta resolução para análise dos diâmetros da artéria braquial e fluxos bem como determinação do débito cardíaco em repouso, após HR e após exercício. Foram calculados o índice de fluxo sistólico na artéria braquial e o índice cardíaco. RESULTADOS: Houve aumento do índice de fluxo sistólico na artéria braquial nas condições HR e exercício físico sendo maior nessa última. Houve aumento do índice cardíaco nas condições de estudo comparativamente ao repouso. CONCLUSÃO: O exercício físico resistido, na carga avaliada, aumenta o fluxo sanguíneo local de forma mais intensa que a HR, constituindo-se numa opção fisiológica à avaliação da disfunção endotelial na IC .

Mathematical analysis of reactive hyperaemia in the isolated rat heart with & without electrical pacing.

Studies were undertaken for a mathematical analysis of reactive hyperaemia in the isolated rat heart with and without electrical pacing and the introduction of a new parameter i.e., rate of reactive hyperaemia, to evaluate reactive hyperaemia. Rate of reactive hyperaemia is represented as a change of coronary perfusion pressure in function with duration of reactive hyperaemia (delta P/DRH). The experiments were performed on the isolated rat heart using constant flow Langendorff's technique. Reactive hyperaemia was induced by interruption of coronary inflow for 30, 60, 120 sec. The electrical pacing produced two-phasic changes in the coronary perfusion pressure (CPP). Restoration of CPP (a long lasting gradual increase of coronary perfusion pressure after the period of ischaemia) correlated well with time following the logistic function. Correlation coefficient was 0.9485 (P < 0.05) with electrical pacing and 0.9892 (P < 0.05) for CPP restoration without electrical pacing. Duration of reactive hyperaemia was significantly (P < 0.05) shorter with electrical pacing than without it. However, the rate of reactive hyperaemia was not significantly different with or without electrical pacing. Fitting of the experimental results as well as the rate of reactive hyperaemia suggest the same mechanism of CPP restoration during the reactive hyperaemia with or without pacing. However, the extent of the phenomenon is significantly affected by pacing.

Relative participation of adenosine and endothelium derived mediators in coronary reactive hyperemia in the dog

The metabolites that mediate coronary reactive hyperemia have not been definitely identified. Although adenosine and endothelium derived substances seem to be involved, their relative contributions have not been defined yet. In the canine coronary circulation, we studied the relative participation of adenosine, nitric oxide and prostacyclin in reactive hyperemia, by measuring the changes produced by interfering with the synthesis or action of these metabolites. The dose-response curve for flow changes vs intracoronary administration of adenosine was displaced to the right after the inhibition of nitric oxide synthesis with N-omega-nitro-L-arginine, revealing that nitric oxide release partly mediates the vasodilator action of adenosine. The inhibition of PGI-2 synthesis with indomethacin did not modify reactive hyperemia. Interference with adenosine action, by administration of adenosine deaminase plus theophylline, decreased reactive hyperemia by 31.0 +/- 4.0 percent (p < 0.001). Inhibition of nitric oxide synthesis decreased reactive hyperemia by a larger (p < 0.005) magnitude, 41.0 +/- 3.9 percent (p < 0.001), revealing the existence of other stimuli for nitric oxide release in reactive hyperemia besides adenosine. Simultaneous inhibition of nitric oxide and PGI-2 syntheses and of adenosine action reduced reactive hyperemia, but the effect was not additive, reaching 49.5 +/- 4.5 percent of control. Since nitric oxide and adenosine are the most important mediators in reactive hyperemia so far described, our results suggest that other metabolites, acting directly or through mediators other than adenosine or nitric oxide, are responsible for about 50 percent of coronary reactive hyperemia